Major objectives of this research are to establish how hormonal and non-hormonal factors (ions, cell-cell interactions) control the growth and differentiation of the female gamete through meiosis and fertilization. Specifically we wish to characterize how the extracellular triggers of oocyte differentiation are transduced within the gametes. In particular we are attempting to identify and characterize the hormonally induced cytoplasmic factors (secondary intracellular messengers) which are produced and control nuclear and cytoplasmic functions. Experiments are being conducted in amphibian, echinoderm and mammalian model systems in order to establish the general nature of these regulatory mechanisms. Major emphasis during the coming year will be given to: (1) The further isolation and characterization of the cytoplasmic and nuclear factors which regulate the transfer of materials across the cell membrane and alter the cell surface; (2) The elucidation of the cytoplasmic mechanism by which the hormone 1-methyladenine controls the differentiation of the sperm nucleus following fertilization; (3) The establishment of what factors control the differential accumulation of steroids in the follicular fluid of mammals and the secretion of steroids by the amphibian follicle cells; (4) The determination of whether liposomes in fact can be used to transfer materials into gametes via the surrounding follicle cells.